The principal goals of this Perinatal Emphasis Research Center are to examine how the developing fetus responds to hypoxia and to provide better methods for assessing health of the fetus and newborn infant. Hypoxia, which can have profound detrimental effects on the developing fetus, has been the common theme of research in this Center since its inception in 1979. In this continuation, experiments will exploit a broad range of expertise from molecular investigations in cell culture to physiological and neurobehavioral studies in fetal animal models and human infants. This multidisciplinary program is organized around five projects linked through a common focus on hypoxia and growth. Specific aims are supported by two core units which provide the necessary administrative, statistical and analytical expertise required by each project. In addition, investigators pursue collaborative aims which foster creativity, enhance productivity, and promote efficient use of experimental subjects and other resources. Research with chronically instrumented pregnant baboons is a special feature of this center because of the similarities in physiological and neurobehavioral development among primates. This research is of fundamental importance, providing knowledge unique to the primate but not available from human studies. Longitudinal studies in pregnant baboons and sheep provide the Center with powerful tools for investigating the integrated responses of the fetus to hypoxemia/hypoxia and growth retardation. Both models are used to evaluate hypotheses concerning responses of immature organisms to variations in specific nutrients which are key to the interpretation of the results from nutrition studies in low birth weight infants. In addition, these models provide a means of testing, in vivo, hypotheses that are generated from cell cultur studies of the placental hormone and endothelial cell prothrombotic responses to hypoxia. By focussing on the mechanisms and extent to which the fetus can maintain adequate function ina the presence of varying degrees of chronic reduction in the supply of oxygen and nutrients, new understanding of the continuum from normal responsiveness and physiological adaptation to pathological decompensation will be obtained. This could provide new approaches to investigations of prenatal events which lead to compromise of the developing child or untoward consequences for health as an adult.